Let me guess...you have comcast for your internet provider? If so go into the comcast routers settings and change the firewall settings from Medium to low if you want a simple easy fix. Low firewall settings is still very much protecting your network so no worries.
This fixed the madden server no connection errors i would get and it also fixed NBA2k14's long period of black screen when it tries to connect to servers and it cannot.
Just a quick google search i found this as well..which confirms my little fix. If you are not on Comcast service provider..than you will need to get into your routers settings and adjust from there. Or do the port forwarding routine if you know how to do that. I do but i am fine with low comcast firewall settings..like i said low settings is more than enough protection.